La Traviata, Royal Opera House, London <br /> LSO/Gergiev, Barbican Hall, London

A few years ago in Leeds, something very surprising happened to me. After a lifetime of rolling my eyes through the last act of La Traviata, tutting at its cruelty and mawkishness, I was shaken by Violetta Valéry's death for the first time. There wasn't much to see on stage – an age-spotted mirror, a dusty chaise-longue, a half-seen ghost of the heroine's hedonistic past – and the singer was not a celebrated diva with a contract to promote expensive timepieces. But where other directors had framed the death of poor, beautiful, consumptive Violetta in yet more beauty, making it limpid, exquisite, unreal, Annabel Arden's stripped-back production for Opera North showed a woman made ugly by illness and loneliness and poverty and fear. All of which is there in the music.

Ever since the lights went down on Arden's production, I've been a sucker for this opera, sniffing into my hanky from the first death-bed chords of the overture. Even bad productions make me cry, and it's all because of that last act, and Janis Kelly's fierce, honest, text-led performance. I cried this Monday at Covent Garden too. Yet I left the star-studded revival of Richard Eyre's 1994 production feeling oddly dissatisfied: moved by Anna Netrebko's fearless reading of Violetta's last, desperate, candid confession, but scandalised that such an uninhibited and spontaneous actress should be shoe-horned into this frigid, fusty show.

Its 10th revival of La Traviata sums up all that is best and worst about the Royal Opera House. Only a handful of companies could afford to field Netrebko, Jonas Kaufmann and Dimitri Hvorostovsky in one cast, and, of those that can, only this house has a chorus of sufficient dynamism to match them and a young artists programme with talents as stage-ripe as Monika-Evelin Liiv (Flora) and Kostas Smoriginas (Marquis). Conductor Maurizio Benini, if over-indulgent of his singers' whims, is a supreme stylist, and the orchestral performance, though slow to warm up, was strong. Musically, all is well. But Eyre's production is a faded relic of the pre-Pappano era, and only Hvorostovsky (Germont) – a marvellous voice in a mannequin's body – adheres to the pre-Pappano protocol of stand-and-deliver singing.

Regrettable as it is that Hvorostovsky has eyes only for Benini, a stiff Germont is not the end of the world. But Bob Crowley's over-stuffed sets and fussy costumes allow for little fluency of movement from anyone. Conceived as a showcase for Angela Gheorghiu, the production calls for poignancy and passivity: a creamy voice in a pretty face. Netrebko, though pretty, is a different animal. Her dark, giddy, uneven voice has less polish than Gheorghiu's, more sprezzatura, more appetite. And if the touchstone of this production is death, Netrebko's – and Verdi's, for that matter – is the process of dying. Revival director Patrick Young has assisted Netrebko to some degree by replacing the overture's memorial portrait with images that suggest Violetta's progress from little matchgirl to pubescent plaything, and has attempted to illustrate a powerful sexual attraction between her and Alfredo, though the chemistry is weak.

Kaufmann's singing is beautiful but unidiomatic, his characterisation diffident, as though he is ashamed of Alfredo for loving Violetta too little, too late, and would prefer to be acting in a production that critiques the opera. But this is Netrebko's moment, and though her bronchitic bark, flushed cheeks, urgent physicality and desperate eyes are undermined by the buttressed costumes she is made to wear in Acts I and II, and her restless spinning suggests she is still in thrall to Willy Decker's modern-dress Salzburg Festival production, she stamps her vitality on the role: underscoring each repeat of "follia" (madness), grasping with both hands her only chance of love, resisting the death she knows to be inevitable. Liberated by the relatively empty set and simple nightdress of Act III, she tears into each nuance of Violetta's music and words, the rough cry of "E tardi", the misery of "Addio passato", the hopeless fantasy of "Parigi, o cara". For her in-the-now performance alone, it is worth fighting for a ticket for this in-the-then show. If Netrebko isn't big enough to merit a new production of La Traviata, it looks as if we're going to be stuck with this one for a few years more.

Valery Gergiev's Mahlerian rollercoaster ride with the London Symphony Orchestra looped back to the beginning last weekend in a riveting performance of the composer's Symphony No 1 and an unriveting performance of Schoenberg's constipated Pelleas und Melisande. Like Netrebko's Violetta, Gergiev's Mahler was lived rather than rehearsed: vital, reckless, thrilling. In the first movement, the faint skein of vibrato-free violins seemed not so much to have started as to have been there all along, unheard, part of a sublime landscape in which Gergiev acted as cinematographer, zooming in to the dense forest of clarinets, then swooping down to a meadow of silken cellos. The stamping, heel-of-the-bow Ländler gave way to a teasingly slow Trio, while the queasy funeral march, Mahler's most overtly Jewish music, encapsulated everything from the casual prejudice of a Viennese sophisticate to the violence of the pogroms. Yes, the accelerandi were insanely fast. But the sinus-clearing shriek of the last movement was one of the most exciting things I've heard from the LSO. For those who missed it, and Symphonies 3, 4, and 6, Radio 3 broadcasts the concerts from 28 January.

Royal Opera House (020- 7304 4000), to 29 January

Need to know

Adapted from Alexandre Dumas' play 'La Dame aux Camélias', Verdi's 'La Traviata' premiered in Venice in 1853 under the straight-talking title 'Amore e Morte'. The first soprano to sing the role of Violetta Valéry was Fanny Salvini-Donatelli, whose weight of "precisely 130 kilograms" made her an unconvincing consumptive, and the premiere was not a success. More slender Violettas have included Maria Callas, pictured below, Teresa Stratas and Angela Gheorghiu, for whom the current Covent Garden production was created. Anna Netrebko's Salzburg Festival performance can be seen on DVD (Deutsche Grammophon), with Rolando Villazon as Alfredo and Thomas Hampson as Germont.

Further reading Susan Sontag's "Illness as Metaphor and Aids and Its Metaphors" (Penguin Modern Classics)